Does Cold Weather Affect a Peace Lily?

Peace lily flowers occur on a central spadix surrounded by a spathe.

Valued for its bold green foliage, clean white spathes on tall stalks and ability to withstand low light, peace lily (Spathiphyllum hybrid) is a reliable houseplant. Native to tropical areas of Central America, Malaysia and the Philippines, cultivated peace lilies are hybrids, and more than 30 named cultivars exist. Peace lily is hardy in U.S. Department of Agriculture plant hardiness zones 10b to 13, because shoots are injured by even light frosts.

Chilling Injury

Not only is peace lily damaged or killed by freezing temperatures, it is also sensitive to chilling temperatures above freezing. Although the plant has long been thought to be relatively resistant to cooler temperatures compared with other tropical foliage plants, a study by members of the University of Florida's Environmental Horticulture department showed that peace lily can be damaged by temperatures from just above 32 degrees Fahrenheit to 59 degrees Fahrenheit. The amount of damage plants experienced depended on the size of the plant, the maturity of the leaves and the amount and duration of the cold.

Kinds of Damage

When exposed to 38 degrees Fahrenheit, chilling injury showed within 24 hours for a small cultivar and within five days for a larger one in the University of Florida study. The damage began at the leaf tips and spread inwardly, with soft, brown areas turning black and then drying up. Mature leaves suffered more than younger leaves. Some plants died. The degree of damage depended on the cultivar. In addition, prolonged exposure resulted in greater damage. Peace lilies treated with 45 degree Fahrenheit temperatures also showed damage, but less than that of the plants given colder temperatures. The cultivars "Annette" and "Debbie" showed the most resistance to cold damage, with "Viscount" and "Classic Viscount" showing intermediate resistance.

Growth Reduction

Peace lilies exposed to 52 degree Fahrenheit temperatures for five to 10 days didn't show any visible damage, but they were still affected by the cold in the University of Florida study. Their growth rate slowed appreciably for as long as 45 days despite having optimal temperatures and nutrition following the cold exposure. In general, peace lily survives at temperatures between 40 and 100 degrees Fahrenheit, but for best growth, keep your peace lily between 68 and 85 degrees Fahrenheit during the daytime and 10 degrees cooler at night.

Cultivation

In addition to protecting peace lilies from low temperatures, avoid placing them in direct sunlight. These plants also prefer a somewhat potbound condition. A quality houseplant mix containing peat moss, bark and sand is suitable for peace lily pots. Keep the plants moist but not soggy, and let the soil to dry between waterings. Allow the water to sit for a few hours so that chlorine evaporates and the liquid reaches room temperature before you water the plant. Brown leaf tips can indicate the humidity is too low. Place the peace lily pot on a pebble tray or mist it occasionally to raise the humidity. It will reward you by helping to remove pollutants such as formaldehyde, benzene and carbon monoxide from the air.

About the Author

Cathryn Chaney has worked as a gardening writer since 2002. Her horticultural experience working in the nursery industry informs her garden articles, especially those dealing with arid landscaping and drought-tolerant gardening. Chaney also writes poetry, which has appears in "Woman's World" magazine and elsewhere. Chaney graduated from the University of Arizona in 1992 with a Bachelor of Arts in English.